1.1 Field of the Invention
The present invention generally relates to method and system for controlling network traffic and relates particularly to such method and system for optimizing network traffic control in a network in which at least most of the transports are package-oriented.
1.2. Description and Disadvantages of Prior Art
Although the present invention is applicable to a broad variety of transport processes—including computer data communication processes—in which some transport objects, i.e. package-like loads are moved along the network's path ways the invention is disclosed herein by focusing on an embodiment thereof in which goods are transported by lorries managed by a haulage enterprise and being moved during their tours across a geographical region which is structured by a plurality of transport paths between respective nodes which are generally equipped with a depot for temporarily stocking some loads of goods. Thus, a transport system is established comprising some basic system elements, as are principally the nodes for receipt, delivery and reload/load divide activities and the vehicles transporting the goods. In electronic data communication these system elements are buffers located at node servers and processors with corresponding data connections as transport means.
Today's requirements concerning the just-in-time delivery of goods are increasing due to a permanent cost reduction process reducing particularly the cost of stocking goods or any parts being involved in an industrial production process. This tendency is even expected to be enforced as goods can quickly be ordered via an online order, e.g. via Internet, an instrument by which the ordering client generally expects a quick execution of his order.
In order to achieve said increasing requirements and demands the provider of such delivery services, speditions, etc., employ staff who's job is to generate schedules comprising time planning and loading or reloading planning for the particular orders. Generally they work computer assisted and use electronically stored data concerning order data, transport vehicle data and node depot data.
A further class of such planning tools helps the person disposing said goods to involve particular client orders into the total good shipping concept. In this area of operative disposition the current total situation of the available fleet of transport vehicles which can vary from bicycle to heavy load lorries includes the permanent location monitoring of the vehicles, e.g. via GPS (global positioning system) or via mobile communication. See, for reference, ‘Freight Transportation. Special Issue of the Annals of Operations Research’, Vol. 16, 1995.
Amongst others, the following parameters are involved therein:
Orders are to be loaded within a load window and have to be delivered within a delivery window. Goods can be transported including intermediate stocking in node depots. By reloading and load division suborders are generated internal to the provider's competence and generally not known to the client. These suborders can also extend only between node depots, so-called inter-depot suborders and include so-called transshipment processes, too, i.e. when a certain load is transported together with others out of economic reasons and is thereby not transported on the direct way to its destination.
Transport vehicles having a given maximum load capacity are available during a given time frame and in a given geographical area.
Depots, normally situated at a node can stock temporarily a given maximum stocking quantity.
A special planning for a particular vehicle and loading schedule referring to passed or future time sections of the planning period.
Loading time windows and delivery time windows and further restrictions special to the particular branch concerned have to be considered, too.
Further restrictions referring to the above said items and parameters are known to a person skilled in the art.
Even when the orders are known at the begin of the total planning period an extensive optimization of a certain number of transports including load division and reloading can not be achieved, as an optimization of such a ‘static’ freight transportation problem is beyond a human operator's capacity.
If the formulation of the optimization problem is viewed time dependent each reload or load division changes the total system involved in the optimization process. Thus, inter-dependencies between particular vehicle time schedules and other parameters mentioned above may possibly vary globally the network traffic situation if only one condition changes. Thus, only reload—including combining of loads—or load division—which are both basically a good instrument for optimization—can be involved to optimization which are known at the begin of the planning period.
As the daily experience shows that even external variations outside the influence of the dispatcher emerge often unexpectedly as can be e.g. accidents, traffic jams, etc., the optimization problem is very difficult to solve.
1.3. Objects of the Invention
The primary object of the present invention thus consists in providing a method for optimizing package-oriented network traffic control which is able to involve amongst static constraints dynamically emerging constraints, too. Thus, tour and loading/reloading schedules should be automatically generated and updated if they exist already, according to the current overall network traffic situation and freshly incoming orders. It should be noted that ‘reloading’ is intended to include deposition, delivery, and receipt of transport objects, i.e. material loads or subloads or, alternatively, in computer communication terminology data packets, at any dedicated location in the network.
It is another object of the present invention to provide user interface means for user interaction with a computer program implementing the inventional method.
It is yet another object of the present invention to provide an application of said method to electronic network communication systems.